Metabolic rate and aging: effects of food restriction and thyroid hormone on minimal oxygen consumption in rats

R. J. McCarter, J. T. Herlihy, J. R. McGee

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Metabolic rate (MR) is widely regarded as an important component of aging processes. Decreased MR has been suggested as a possible mechanism of the life-prolonging action of food restriction in rodents and recent reports show lowered plasma levels of tri-iodothyronine (T3), a regulator of MR, in food restricted rodents. In order to study the relationship between MR, food restriction, thyroid status and aging we measured the Minimal Oxygen Consumption (MOC) of barrier-raised Fischer 344 male rats fed ad libitum (Group A) or fed a diet restricted to 60% of ad libitum intake (Group R). Oxygen consumption (VO2) was also measured over 24 hr to establish the relationship between MOC and VO2 under usual living conditions. Results show: (i) MOC declines with age in both groups of rats; (ii) there is no difference in MOC of Groups A and R rats; (iii) MOC of Group R rats is significantly more sensitive to doses of injected T3 than MOC of Group A rats at all ages; and (iv) MOC of both groups of rats is significantly lower than the lowest VO2 recorded under usual living conditions. The results indicate that a decrease in MR is not the mechanism by which food restriction retards aging processes in rodents. The results also suggest no change in thyroid status due to restriction of food although there is increased sensitivity to T3 in food restricted rats.

Original languageEnglish (US)
Pages (from-to)71-76
Number of pages6
JournalAging Clinical and Experimental Research
Issue number1
StatePublished - Sep 1989


  • food restriction
  • Metabolic rate and aging
  • minimal oxygen consumption
  • thyroid hormone

ASJC Scopus subject areas

  • Aging
  • Geriatrics and Gerontology


Dive into the research topics of 'Metabolic rate and aging: effects of food restriction and thyroid hormone on minimal oxygen consumption in rats'. Together they form a unique fingerprint.

Cite this